Answer :
To find the radius of the planet in units of Earth radii [tex](\(R_E\))[/tex] and Jupiter radii [tex](\(R_J\))[/tex], we need to use the provided orbital radius and the physical characteristics of the star. Here's how we can calculate it:
Given data:
- Orbital radius of the planet [tex](\(r\))[/tex]: \(0.76841\)[/tex] AU
- Stellar radius [tex](\(R_*\))[/tex]: \(2.69\)[/tex] times the radius of the Sun [tex](\(R_\odot\))[/tex]
Step-by-step calculations:
1. Convert the orbital radius to kilometers (km):
- 1 AU (Astronomical Unit) = [tex]\(1.496 \times 10^8\) km[/tex]
- Orbital radius \(r\)[/tex] in kilometers:
[tex]\[r = 0.76841 \times 1.496 \times 10^8 \text{ km}[/tex]
[tex]\[ r \approx 1.149 \times 10^8 \text{ km}\][/tex]
2. Calculate the radius of the star in kilometers:
- Given[tex] \(R_* = 2.69 R_\odot\)[/tex]
- Assume [tex]\(R_\odot = 695,700\)[/tex] km (average radius of the Sun)
- Stellar radius \(R_*\)[/tex] in kilometers:
[tex] \[R_* = 2.69 \times 695,700 \text{ km}\][/tex]
[tex]\[ R_* \approx 1,868,893 \text{ km}\][/tex]
3. Determine the planet's radius in Earth radii [tex](\(R_E\))[/tex]:
- Assume Earth's radius [tex]\(R_E = 6,371\)[/tex] km
- Planet's radius [tex]\(R_{\text{planet}}\) in \(R_E\):\[R_{\text{planet}} = \frac{r}{R_E}\][/tex]
[tex]\[R_{\text{planet}} = \frac{1.149 \times 10^8\text{ km}}{6,371 \text{ km}}\][/tex]
[tex]\[R_{\text{planet}} \approx 18,016\][/tex]
4. Calculate the planet's radius in Jupiter radii [tex](\(R_J\)):[/tex]
- Assume Jupiter's radius [tex]\(R_J = 69,911\)[/tex] km
- Planet's radius [tex]\(R_{\text{planet}}\)[/tex] in \(R_J\)[/tex]:
[tex]\[R_{\text{planet}} = \frac{r}{R_J}\][/tex]
[tex] \[R_{\text{planet}} = \frac{1.149 \times 10^8 \text{ km}}{69,911 \text{ km}}\][/tex]
[tex]R_{\text{planet}} \approx 1,643[/tex]
Summary:
- Planet's radius [tex]\(R_{\text{planet}} \approx 18,016 R_E\)[/tex]
- Planet's radius [tex]\(R_{\text{planet}} \approx 1,643 R_J\)[/tex]
These calculations give us the planet's radius relative to Earth and Jupiter based on the provided orbital radius and the characteristics of the star.
